The antonyms or opposite of the phrase "is stuck on" could be "is detached from," "is free from," or "is released from." These antonyms could be used in different contexts, such as when referring to a physical object that was previously attached to another, or when depicting a person's mindset that was once fixed on something but has now moved on. For example, "The magnet is detached from the metal surface," "The sticker is free from the book cover," or "She released herself from the negative thoughts that were holding her back." These phrases provide a sense of liberation and freedom, emphasizing the idea of breaking away from something that previously held one back.